The present invention relates to a process for making a panel such as a leaf having a supported member comprised of a glazed part either of a simple or multiple sheet construction to accommodate the panel for use as a window or a door capable of swinging, oscillating or sliding movement and a supporting part member comprised, for example, of shaped parts.
Panels which comprise a supporting frame and a glass window which is mounted by the supporting frame and secured by a mastic capable of providing both a mechanical bond and seal between the supporting frame and the glass window are known in the prior art. These panels, however, have not recognized an acceptance because of costs in fabrication. To this end, it was considered that the supporting frame need be comprised of strong constituent components thereby to provide the panel with the dimensional stability and mechanical strength required for use. The constituent components of such supporting frames often are relatively expensive. Furthermore, the techniques followed in the process of assembling such panels to assure that the supporting frame does not impart undue mechanical stress to the edges of the glass window are of a precision nature, introducing a measure of added cost.
Thus, it has been suggested to employ a simple frame which may be glued or bonded directly and rigidly on the glass window generally with a hard mastic, wherein the rigidity of the panel derives from the glass window rather than the frame. The simple frame may be much lighter than the frame of the panel described above and may consist of shaped parts of thin cross section. The shaped parts have been formed of wood, plastic, a light alloy, and so forth. The hard mastic forms a rigid bond to the edges of the glass window over their entire length and the junctions in the angles are provided without any special contrivance.
Some glass windows are of double thickness, formed by a pair of glass parts which have welded edges. Oftentimes there are irregularities along the welded edges and it has been suggested that such irregularities may be corrected by receipt of one or more pads therealong and then subjecting the pad or pads to a machining operation to create a rectilinear edge. The frame then may be received on the glass window and centered by the rectilinear edge preparatory to other operations.
It is necessary to prevent mechanical stress along the edges of a glass window, particularly the welded edges of double thickness glass windows. A supporting frame of the former type, while it could be used in fabrication of the panel, would continue to suffer from the problems of expense which would be increased by costly expenses of machining. And, if a simple frame were used in fabrication it still would be glued directly and rigidly onto the faces of the glass window along the edges with the attendant problems of introduced mechanical stress. Thus, the double thickness glass windows are not sufficiently freed from the problems associated with the fragility of their edges.
Processes utilizing simple frame panels have advantages over the prior art panels fabricated with a rigid supporting frame generally in the area of the costs involved. However, they also have various drawbacks which are important in the overall view of the prior art. In particular, the known manufacture of the panel militates against the recovery of parts in the event of breakage of the glass window. Furthermore, the assembly of the panel requires a great deal of care and precision to reduce the mechanical stress along the edges of the glass window and they are not always subject to mass production techniques because of the variation in size of the glass window. Since mass production techniques are not always possible it has been necessary to carry out the assembly of panels of this type at the site of the operation, rather than in the factory, and as such the assembly requires the availability at the site of specialized workshops and qualified personnel. This all results in a rather low production rate and a rather high cost of a finished product.